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Metabolite Patterns as Potential Biomarkers and Therapeutic Targets for Persistent Asthma
S78 Abstracts
299
SUNDAY
Metabolite Patterns as Potential Biomarkers and Therapeutic Targets for Persistent Asthma N. Yang, B. Jayaprakasam, J. Wisnivesky, E. Halm, X. Li; MountSinai School of medicine, New York City, NY. RATIONALE: Metabolomic research focuses on analysis of metabolites in human tissues and biofluids. We employed this method to compare metabolite patterns in plasma of asthmatics and healthy control subjects. METHODS: Plasma samples were obtained from 8 patients with persistent moderate to severe asthma and 4 healthy controls. 300mL of plasma sample was extracted with 1 mL of acidic methanol (1% formic acid). After centrifugation, the supernatant was collected and concentrated. 20 mL of the concentrated supernatant was injected to the Liquid-ChromatographyMass-Spectrometry (LC-MS). The linear gradient, 98% to 10% of mobile phase A: H2O (0.1% formic acid) and 2% to 90% of mobile phase B: CH3CN (0.1% formic acid), over 35 min was performed. RESULTS: Clear differences between asthmatics and healthy controls were found in the total ion current plot (TIC) of plasma. Major peaks eluting at 6.09, 9.98, 13.01, 14.96 and 18.21 min were found in the plasma of the asthmatics, but not in healthy controls. Using the human metabolome database, we identified that the peak eluting at 6.09 min corresponds to Tyrosine; the eluting at 9.98 min corresponds to Diacylglycerol; the eluting at 13.01 min corresponds to Phenylserine; the eluting at 14.96 min corresponds to Ergothioneine, which is a metabolite of Histidine; the eluting at 18.21 min corresponds Ethenodeoxyadenosine. All these identified metabolites are related to inflammation or oxidative stress. CONCLUSION: We have generated the metabolic fingerprint/profile of plasma from asthmatics using LC-MS approach, which may eventually lead to biomarkers or therapeutic target for persistent asthma. Funding: MountSinai School of Medicine
300
Exercise Challenge Test in Relation to Methacholine Challenge Test in Young Asthmatics Y. Shin1,2, Y. Lee1,2, Y. Jung1, C. Hong1,2, J. Park1,2; 1Division of Allergy and Immunology Department of Internal Medicine, Seoul, REPUBLIC OF KOREA, 2Institute of Allergy, Yonsei University College of Medicine, Seoul, REPUBLIC OF KOREA. RATIONALE: Exercise can induce airway hyperresponsiveness by release of mediator from mast cells and rebound vascular dilation, and the mechanisms are quite different from that of the methacholine challenge test (M-test). However the relationship between M-test and exercise challenge test is not well studied. METHODS: Sixty-eight young symptomatic patients (M:F 5 64:4, mean age 5 21.51 6 5.93 years) who were diagnosed as asthma with M-test (Methacholine PC20 < 8 mg/ml) were recruited to this study. Exercise challenge test (E-test) by 15 minute running on treadmill was done 48 hrs after M-test. RESULTS: Among sixty-eight asthma patients, only thirty-six patients (52.9%) showed positive response to exercise. Methacholine Log(PC20) is lower in positive responder to exercise than non-responder group (-0.1685 6 0.5148 mg/ml vs. 0.3429 6 0.3882 mg/ml, p < 0.001). There was no significant difference in age, gender, presence of atopy, peripheral blood eosinophils, % of eosinophil in sputum, and spirometric lung functions. CONCLUSIONS: E-test is less sensitive than M-test for diagnosis of asthma and the positive responders have more intense methacholine airway hyperresponsiveness than the others.
301
Is Tidal Breathing Analysis Useful for Diagnosis of Airway Obstruction in Children? S. Filtchev1, V. Dimov2, M. Yankova1, K. Uzunova-Dimova2, S. Randhawa3; 1Pediatric Clinic, Alexandrovska Hospital, Medical University Sofia, Sofia, BULGARIA, 2Cleveland Clinic, Cleveland, OH, 3Private practice, Fort Lauderdale, FL. RATIONALE: The aim of the study was to assess the validity of tidal breathing parameters such as Tpef%Te (percent ratio of time to reach peak tidal expiratory flow to the total expiratory time) for diagnosis of airway obstruction in children.
J ALLERGY CLIN IMMUNOL FEBRUARY 2008
METHODS: We used a computer analysis program (Masterscreen, Jaeger) for tidal breathing evaluation. Tidal breathing and forced expiratory patterns were analyzed in 72 healthy controls, 105 children with asthma, and 17 children with cystic fibrosis (CF), aged 4-18 years. RESULTS: The three groups differed significantly in forced expiratory volume in 1 second (FEV1) as percent of predicted: 114.5% in controls; 87.7% in asthmatics, and 67.1% in CF. Tpef%Te did not differ among groups: 34.8% in controls; 33.5% in asthmatics; and 34.3% in CF patients. Tpef%Te ratios did not correlate with any anthropometrical parameters in controls nor with forced expiratory flow values in children with asthma. Twenty eight of asthmatics with severe obstruction underwent measurements before (FEV1 67.0%; Tpef%Te 28.1%) and after bronchodilation with albuterol (FEV1 97.1%; Tpef%Te 33.5%). In contrast to the significant changes in FEV1 (p less than 0.001), the differences in Tpef%Te were not statistically significant (p higher than 0.05). CONCLUSIONS: Tidal breathing parameter Tpef%Te was not sensitive enough for diagnosis of airway obstruction in children in our study. It could not be applied to quantify bronchial challenge in individual patients.
302
Association Of Body Composition With Bronchial Hyperresponsiveness J. Chung, S. Yu, K. Shin, K. Lee; Yeungnam University Hospital, Daegu, REPUBLIC OF KOREA. RATIONALE: The prevalence of asthma is increasing worldwide. There are several cross sectional and longitudinal studies showing obesity or increased body mass index appears to increase th risk of asthma, wheezing and bronchial hyperresponsiveness (BHR) in adults. We investigated the association of each body composition in addition to body mass index with BHR. METHODS: This study involved a retrospective review of existing records of 234 subjects with respiratoy symptoms, who underwent pulmonary function test, methacholine challenge test and body composition test from January 2002 to August 2006. RESULTS: Of the 234 subjects, 113(48%) were female. The median age was 47 years for females and 36 years for males. There was no significantly difference of body mass index, fat mass and fat free mass between BHR negative group and positive group in male. But In female, Body mass index was 23.2 Kg/m2 and 25.2 Kg/m2 in BHR negative group and positive group (p < 0.05). Fat mass percent was 29.1% and 34.3% in bronchial BHR negative group and positive group (p < 0.05). Fat free mass percent was 70.3% and 65.8% in BHR negative group and positive group (p < 0.05). CONCLUSIONS: This study showed significant differences in body mass index, fat mass and fat free mass between BHR negative group and positive group in female. But there was no significant difference in male. Increased BHR is strongly associated with fat mass and fat free mass in addition to body mass index in women.
299
SUNDAY
Metabolite Patterns as Potential Biomarkers and Therapeutic Targets for Persistent Asthma N. Yang, B. Jayaprakasam, J. Wisnivesky, E. Halm, X. Li; MountSinai School of medicine, New York City, NY. RATIONALE: Metabolomic research focuses on analysis of metabolites in human tissues and biofluids. We employed this method to compare metabolite patterns in plasma of asthmatics and healthy control subjects. METHODS: Plasma samples were obtained from 8 patients with persistent moderate to severe asthma and 4 healthy controls. 300mL of plasma sample was extracted with 1 mL of acidic methanol (1% formic acid). After centrifugation, the supernatant was collected and concentrated. 20 mL of the concentrated supernatant was injected to the Liquid-ChromatographyMass-Spectrometry (LC-MS). The linear gradient, 98% to 10% of mobile phase A: H2O (0.1% formic acid) and 2% to 90% of mobile phase B: CH3CN (0.1% formic acid), over 35 min was performed. RESULTS: Clear differences between asthmatics and healthy controls were found in the total ion current plot (TIC) of plasma. Major peaks eluting at 6.09, 9.98, 13.01, 14.96 and 18.21 min were found in the plasma of the asthmatics, but not in healthy controls. Using the human metabolome database, we identified that the peak eluting at 6.09 min corresponds to Tyrosine; the eluting at 9.98 min corresponds to Diacylglycerol; the eluting at 13.01 min corresponds to Phenylserine; the eluting at 14.96 min corresponds to Ergothioneine, which is a metabolite of Histidine; the eluting at 18.21 min corresponds Ethenodeoxyadenosine. All these identified metabolites are related to inflammation or oxidative stress. CONCLUSION: We have generated the metabolic fingerprint/profile of plasma from asthmatics using LC-MS approach, which may eventually lead to biomarkers or therapeutic target for persistent asthma. Funding: MountSinai School of Medicine
300
Exercise Challenge Test in Relation to Methacholine Challenge Test in Young Asthmatics Y. Shin1,2, Y. Lee1,2, Y. Jung1, C. Hong1,2, J. Park1,2; 1Division of Allergy and Immunology Department of Internal Medicine, Seoul, REPUBLIC OF KOREA, 2Institute of Allergy, Yonsei University College of Medicine, Seoul, REPUBLIC OF KOREA. RATIONALE: Exercise can induce airway hyperresponsiveness by release of mediator from mast cells and rebound vascular dilation, and the mechanisms are quite different from that of the methacholine challenge test (M-test). However the relationship between M-test and exercise challenge test is not well studied. METHODS: Sixty-eight young symptomatic patients (M:F 5 64:4, mean age 5 21.51 6 5.93 years) who were diagnosed as asthma with M-test (Methacholine PC20 < 8 mg/ml) were recruited to this study. Exercise challenge test (E-test) by 15 minute running on treadmill was done 48 hrs after M-test. RESULTS: Among sixty-eight asthma patients, only thirty-six patients (52.9%) showed positive response to exercise. Methacholine Log(PC20) is lower in positive responder to exercise than non-responder group (-0.1685 6 0.5148 mg/ml vs. 0.3429 6 0.3882 mg/ml, p < 0.001). There was no significant difference in age, gender, presence of atopy, peripheral blood eosinophils, % of eosinophil in sputum, and spirometric lung functions. CONCLUSIONS: E-test is less sensitive than M-test for diagnosis of asthma and the positive responders have more intense methacholine airway hyperresponsiveness than the others.
301
Is Tidal Breathing Analysis Useful for Diagnosis of Airway Obstruction in Children? S. Filtchev1, V. Dimov2, M. Yankova1, K. Uzunova-Dimova2, S. Randhawa3; 1Pediatric Clinic, Alexandrovska Hospital, Medical University Sofia, Sofia, BULGARIA, 2Cleveland Clinic, Cleveland, OH, 3Private practice, Fort Lauderdale, FL. RATIONALE: The aim of the study was to assess the validity of tidal breathing parameters such as Tpef%Te (percent ratio of time to reach peak tidal expiratory flow to the total expiratory time) for diagnosis of airway obstruction in children.
J ALLERGY CLIN IMMUNOL FEBRUARY 2008
METHODS: We used a computer analysis program (Masterscreen, Jaeger) for tidal breathing evaluation. Tidal breathing and forced expiratory patterns were analyzed in 72 healthy controls, 105 children with asthma, and 17 children with cystic fibrosis (CF), aged 4-18 years. RESULTS: The three groups differed significantly in forced expiratory volume in 1 second (FEV1) as percent of predicted: 114.5% in controls; 87.7% in asthmatics, and 67.1% in CF. Tpef%Te did not differ among groups: 34.8% in controls; 33.5% in asthmatics; and 34.3% in CF patients. Tpef%Te ratios did not correlate with any anthropometrical parameters in controls nor with forced expiratory flow values in children with asthma. Twenty eight of asthmatics with severe obstruction underwent measurements before (FEV1 67.0%; Tpef%Te 28.1%) and after bronchodilation with albuterol (FEV1 97.1%; Tpef%Te 33.5%). In contrast to the significant changes in FEV1 (p less than 0.001), the differences in Tpef%Te were not statistically significant (p higher than 0.05). CONCLUSIONS: Tidal breathing parameter Tpef%Te was not sensitive enough for diagnosis of airway obstruction in children in our study. It could not be applied to quantify bronchial challenge in individual patients.
302
Association Of Body Composition With Bronchial Hyperresponsiveness J. Chung, S. Yu, K. Shin, K. Lee; Yeungnam University Hospital, Daegu, REPUBLIC OF KOREA. RATIONALE: The prevalence of asthma is increasing worldwide. There are several cross sectional and longitudinal studies showing obesity or increased body mass index appears to increase th risk of asthma, wheezing and bronchial hyperresponsiveness (BHR) in adults. We investigated the association of each body composition in addition to body mass index with BHR. METHODS: This study involved a retrospective review of existing records of 234 subjects with respiratoy symptoms, who underwent pulmonary function test, methacholine challenge test and body composition test from January 2002 to August 2006. RESULTS: Of the 234 subjects, 113(48%) were female. The median age was 47 years for females and 36 years for males. There was no significantly difference of body mass index, fat mass and fat free mass between BHR negative group and positive group in male. But In female, Body mass index was 23.2 Kg/m2 and 25.2 Kg/m2 in BHR negative group and positive group (p < 0.05). Fat mass percent was 29.1% and 34.3% in bronchial BHR negative group and positive group (p < 0.05). Fat free mass percent was 70.3% and 65.8% in BHR negative group and positive group (p < 0.05). CONCLUSIONS: This study showed significant differences in body mass index, fat mass and fat free mass between BHR negative group and positive group in female. But there was no significant difference in male. Increased BHR is strongly associated with fat mass and fat free mass in addition to body mass index in women.